QUALITY CHANGES IN HTST PROCESSING OF RICE PARBOILING

Paddy soaked to saturation level, when treated at a high temperature for a short time in a mechanical sand roaster is parboiled and dried in a single pass of 47 s duration. The extent of drying depends on the sand temperature. The sand temperature is critical as it decides the associated quality changes in the milled rice. Even at a sand temperature of 125 degrees C, paddy could fully be parboiled but with mild effect. The parboiling became severe at high temperatures. Roasting the soaked paddy at 250 degrees C, reduced the cooking time of the resultant milled rice. A sand temperature of 125-150 degrees C was considered suitable for producing normal parboiled rice by this technique.